Mechanisms for periodically feeding materials in carefully metered quantities



A. E. THIEMANN El AL J ne 16,1959

MECHANISMS FOR PERIODICALLY FEEDING MATERIALS IN CAREFULLY METERED QUANTITIES Fi led June 5, 1957 2 Sheets-Sheet 1 INVENTORS ALBERT EATHIEMANN.

BY HANS HAINZL.

M 6. Ow-v ATTORNEY June 16, 1959 A. E. THIEMANN ETAL 2,891,175

MECHANISMS FOR PERIODICALLY FEEDING MATERIALS IN CAREFULLY METERED QUANTITIES Filed June 5, 1957 2 Sheets-Sheet 2 l I L L 35 '36 BY HANS HAINZL.

Mag/5W ATTORNEY.

United States Patent MECHANISMS FOR PERIODICALLY FEEDING MATERIALS IN CAREFULLY METERED QUANTITIES Albert Ernst Thiemann and Hans Hainzl, Astoria, NY.

Application June 5, 1957, Serial No. 663,715

Claims. (Cl. 307-112) This invention relates to feeding mechanism and more particularly to such mechanisms that are used for periodically feeding materials in carefully metered quantities.

This invention is particularly adapted for the periodic feeding of chemicals in liquid form to a bulk liquid which must be kept in a desired condition such as alkaline, neutral, acid or containing a more or less constant percentage of a constituent that may be lost in a number of ways. For example, cooling water for refrigeration equipment may gradually build up acidity if the water is recirculated in an atmosphere containing sulfur. In other localities the Water may be hard so that scale or cmst forms on the heat exchange coils if acid is not added.

In treatments of this type the amount of treating material required is not large relative to the amount of water to be treated. For this reason many maintenance operators have attempted to add large quantities of treating material once a season expecting that ample protection to the system will always result. This is particularly harmful when the treating material is acid.

Generally, even periodic manual treatments are of little value because of the difliculty in determining how large a dose to add. Acidity tests after dosing mean very little unless the dosing material has become well distributed through the system.

We have found that after a slight study of the general locality a fairly good approximation of the dosing requirements can be obtained. This will take into consideration usual air pollution, average temperature, humidity, loss of water by windage, type of water and a number of less important factors. The regularity and frequency of the dosing is important since this enables occasional analyses or pH checks to be of worthy meaning.

One of the objects of this invention is to provide a device which will pump a predetermined amount of dosing solution to the water to be treated at regular intervals.

Another object is to provide a timing mechanism for periodically connecting a source of current to a load and disconnecting the source after a predetermined length of time.

These objects are attained in a dosing device which, briefly stated, includes a pump for pumping dosing solution and a control mechanism for periodically starting the pump and then stopping the pump after a relatively short running period.

In the accompanying drawing showing, by way of example, one of many possible embodiments of the invention,

Figure l is a perspective of the device, with fragments of parts removed, shown in connection with a source of dosing solution and a water tank;

Figures 2 through 5 are schematic representations of the control mechanism showing positions thereof in the sequence of normal operation, and

Figures 6 and 7 are front and side views of a detail of the mechanism.

The invention comprises a case 10 adapted to be hung on a wall and containing a control device, generally designated 11, including a constantly running clock 12, a metering timer 14, and switch means 15 responsive to said clock and timer in a manner described in detail below.

The control device governs the action of a. motor 16 within the case and is energized by a source of commercial current S having live and ground lines L and G as obtained from an ordinary outlet 18 and, when operating, drives a pump 19 for transferring dosing solution from a supply 20 to the water to be treated as in a tank 21, the transfer being conducted by inlet and outlet conduits 22 and 24. If the tank 21 is at a greater height than the supply a self-priming pump ought to be used, but if not, then any type of constant displacement pump may be used as long as the motor 16 is substantially a constant speed motor under the operating conditions. In most locations of service the conduits 22 and 24 may be metal or plastic tubing and so require no expensive pipe-fitting. The casing may have a panel cover 25 but it is preferable that the clock and metering timer be not exposed therethrough lest there be tampering with the controls. A remote reading meter to indicate the amount of water in the cooling system is desirable and its indicating parts 26 may be mounted on the panel.

The constantly running clock 12 may be little more than a small synchronous motor having a winding 28 and the usual armature and gearing (not shown) and provided with a dial 29 and a rotary cam 30 having one or more notches 31 depending on the speed of the cam and the desired frequency of dosing. The dial and the cam may be the same physical element. The cam 30 is hereinafter designated as the clock cam and for the example as shown, is geared to make a complete revolution in twelve hours and is provided with two oppositely spaced notches 31 and under these conditions dosing takes place every six hours.

A cam follower 32 rides on the clock cam 30 and is ganged by gauging means shown at 34 to a two-way switch 35, hereinafter designated as the clock switch for selectively connecting a conductor L, sometimes called the live line of the source S to alternate conductors 36 and 38 termed pump and resetting conductors respectively. The ground line G is connected through the winding 39 of the timer 14 to another two-way switch 40 hereinafter called the timer switch for selectively connecting the timer winding to the two alternate conductors 36 and 38. The terms live and ground lines are used largely for purposes of reference rather than a meaning that line G must be connected to the earth.

The timer 14 is similar to the clock 12 except that the cam wheel 41 thereon is geared to run at a much higher speed, say 1 rpm, and is provided with a much wider, and adjustable, low portion or gap 42. Only the winding 39 and shaft 44, on which the cam 41 is mounted, are shown as parts of the timer since such timers are well known to the art. A cam follower 45 rides on the timer cam. Both cam followers are biased by means (not shown) to enter the low parts or notches of the respective cams.

The timer cam 41, shown in detail in Figs. 6 and 7, is made up of inner and outer disks 46 and 48 each having a portion 42a and 4212 [respectively of reduced radius over approximately of the circumference. When these two portions coincide the width of the gap or low part 42 is at a maximum and when in other positions with respect to each other the gap is narrower. The disks are clamped tightly with respect to each other and to the shaft 44 between a wheel plate 49 fast on the shaft and a nut 50 threaded on the outer end of the shaft.

The pump motor 16 is provided with terminals P P the terminal P being connected, through a simple pump switch 51, to the pump conductor 36 and P to the ground line. The timer cam follower 45 is ganged with the pump switch 51 and the timer switch 40 so that when the follower 45 is in the gap 42 the pump switch is in closed position and the timer winding is connected, through the timer switch to the pump conductor 36. When the follower rides high on the earn, the pump switch is open and the timer winding is connected, through the timer switch to the resetting conductor 38.

When the follower 32 of the clock cam 30 is in the notch 31 the live line L is connected, through the clock switch 35 to the pump conductor and when the follower rides high on the cam the live line is connected through the switch, to the resetting conductor.

The operation of the system can best be explained by reference to Figures 2 to 5. In Figure 2, the clock 12 has just thrown switch 35 to connect the live line to the pump conductor energizing timer winding 39 and the pump motor, so as to begin pumping dosing solution and start the timer cam turning in the direction of the arrow. Such action continues, say 15 seconds, depending on the set width of the gap 42, after which the cam 41 throws the pump and timer switches to the positions in Figure 3. The pump switch has been opened and the timer winding 39 has been disconnected from the line pump conductor 36 and connected to the resetting conductor 38. In this short space of time the clock 12 has not affected the clock switch 35.

After some more lengthy period the clock cam shifts the switch 35, as shown in Figure 4, disconnecting the pump conductor 36 from the live line L and connecting the latter to the resetting conductor 38 so that once more the timer winding is energized and the cam 41 is turning as shown by the arrow. In a short length of time the cam 41 turns so that the follower enters the gap as shown in Figure to disconnect the timer winding from the energized resetting conductor 38 and closes the pump switch. The switches then remain as in Figure 5 until the clock recloses the clock switch as in Figure 1 where the cycle is repeated.

By having the timer, in addition to the clock, to control the pump motor, the notches 31 in the clock cam may be made without a great degree of accuracy. That is to say, the clock cam has nothing to do with the duration of the dosing, but merely starts the timer and pump at approximately predetermined times. Corrosion or wear on the clock cam and its follower will not interfere with the duration of the dosing.

The duration of dosing may be adjusted by loosening the knurled nut 50 on the shaft end so that the disks 46 and 48 may be turned with respect to each other so as to vary the width of the gap 42 to correspond to the desired period. The timer, of course, when running, runs at constant speed.

By proper choice of the clock cam speed and the number ofclock cam notches the frequency of dosing may be from, say from once a day to every half hour, and the amount of dosing, depending on the pump capacity and the width of the gap 42 may vary from half an ounce to 5 gallons.

The invention claimed-is:

1. A timing mechanism for periodically energizing a load comprising a fast running timer motor and source of current therefor; first and second two-way switches interposed between the source and motor for complete control over the motor at two separate locations, alternate conductors being provided between the switches for said control; a slow running clock mechanism for periodically throwing the first switch from one connecting position to the other; means operated by the timer motor for shifting the second switch from one connecting position to the other; a load having one terminal connected to one of said conductors and another terminal connected to the source where there is at least potentially a substantial difference in voltage from that of said one of the conductors, and a one-way switch interposed between the load and the one of said conductors, the one-way switch being ganged with the second switch.

2. In a mechanism as claimed in claim 1, the first switch being in connecting position to said one of said conductors long enough for the timer motor to effect a shifting of the second switch.

3. In a mechanism as claimed in claim 1, the first switch being in connecting position with the other of said alternate conductors long enough for the timer motor to effect shifting of the second switch.

4. Ina mechanism as claimed in claim 1, said one-way switch being ganged to be in closed position when the second switch is vin connective position with said one of said conductors.

5. In a mechanism as claimed in claim 4 the relative speeds of the clock and timer motor being such that the timer motor will shift position of the second switch faster than the clock can shift the first switch.

References Cited in the file of this patent UNITED STATES PATENTS 1,773,130 Denniston Aug. 19, 1930 2,019,299 Fox et al. Oct. 29, 1935 2,186,250 Lenehan et a1. Jan. 9, 1940 2,190,060 Fager Feb. 13, 1940 2,517,142 Staley Aug. 1, 1950 2,542,189 Gates et a1 Feb. 20, 1951 

